SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5e8536bd6652304e063445a842a60c939c4c412692b18001da4be20ea951fed' 
  AND token = 'XP6ZpIizNS8+J2/QQ4/bGTPRw0xcTDtvIdRRa4tKr18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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