SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6ba6685dc617d088150a838555759e92538ea05a40a8d91895f20fb3aebee61' 
  AND token = 'yoy+7DUYIiaxM7Fd/SxQjoC5SG3TwxuYFWjnWTbX/4s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}