SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4436479d07b58ae6de26cc0a593fdbebe568ac223c31315765d0ec80b2d86ec1' 
  AND token = 'uMPG/VcFzdv9i0D6IygwEcfoPD/wP1YuMX7E8z2NHQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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