SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14f48fd9a5e2531fc0a1d981988267dd49a35258e0c7f3193e522eb480de5671' 
  AND token = '+/L5Mr0R2+c+pvX7oIMOPPeePn1vG8IjNvNoX+5N5Hs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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