SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61e5ee5565c459e71cb6ba59f69c6283c66558b8f2e90fc90b41f0fbc79cdfdd' 
  AND token = 'pMGUUCtp+ZUaJK2ZkjH+SeEC18TVmTv3onThgig/nXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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