SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9d84906170b615ef262e4ae7747669ae4e03bd9666e24430763e521e13780fe' 
  AND token = 'YutZJ0UDnCsHG7lhrEqZmfmKu2tJX3z4PkGpkhTHVt8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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