SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55a33f9efc821e187a6d7bf0e7e7cd29c36f53d378d4597b255fc8bd9c1aa7b2' 
  AND token = 'njUJmIvlR8BYjFp0Zvu65NqiVGOXXXH7LRuZDBVEr2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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