SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24e132c7058bdd10e29d68630fe86be950dfbb4503775dc75789e80814eea1c5' 
  AND token = '9Z9MTngfmdBUhrM5oPHeBbkbxFLq2jNsRodp0c2RnTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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