SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c1831d9dfe12be9458a6172c808ceb596403663f3265abd0ec4552569c16baa' 
  AND token = 'F0jrbdHCrgs88x7x6JPX1smYgXLPfl6DK0d0pMUwQYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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