SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06a94b82fc5d4869f16ae0f1e1cca0f9b6746d930ddf2b3d845593891bb10450' 
  AND token = 'rYrjPyiyEZKZ0xC/Gn76NjkRlPUEHVdfXcKka7Sjt5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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