SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e34b2b112fa73d9d85918f4020ec4684ecf72994a788054fe8c79c6c869b9d56' 
  AND token = 'wsgfLiUOy+TQZh9iDi/2tFJwOtfVtl5VBunwyEDyIhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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