SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '364395c9f443800b51c1cccf32c27c218405b05fea974e8001af174b77409672' 
  AND token = 'X3MwMxfGe9uXGLvlNvoeT4EAzDLFHDfsMRhZrzGZkHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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