SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '172c6dbf0e95158506a9866e5820a655e48d24845ee608c47e1efbf320227185' 
  AND token = 'jBMUWt0o6wd+g1Uk31dYnrZwA+cSjf5eQTmmldWVsjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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