SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41fbca6155568611ee645e5d9a47de6c91f3d02bf580e2c27f6b7f088b778749' 
  AND token = '5yhgFLYFvbtT5x7p/JDFmtZJRXTCsTw+Dndq0xSrsYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}