SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b28c5c68845587b39891b2172f4a55958a6d3ef4018f111cfb913235172d5a9' 
  AND token = 'e6QRX8orUhvV+Qb6+3SqHGjiQF7q9CPWIfAnYqopHgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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