SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2af4af793c964ff688730e20f9373c652d22f5dc4ab0d12db48df3f707982dc' 
  AND token = 'cjj0LckmGmwvI1BKlHvwkyywdVo7gJgVWtpyDEqH/GE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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