SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '077f762579b19e0bab333433401ca0c532ac14bb1c774186c69acf8151f4736a' 
  AND token = 'JJnStvXRCtKrjGYsnBl4RVEb75iImz1RD1H7KfAeyRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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