SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9236a6278bdb0ae18850d77440e4e6e531820ae426ee818b7ed293fab858b7fa' 
  AND token = 'WonuqQ5ia6QTOWK3zTwOtiCOrLSEOtlS+HK8X7dFT+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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