SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecaabc974b099025eb624e2f0c5a42ba77fec1c1bb66d7138ec5005673f5d8c1' 
  AND token = 'kz4v8WESVfVACiyB738HLGSKPyHjOv17a0/diRfOM3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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