SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f06de0795afaebbda8212576f3b2827975531b7a95343a8429e4d6e568f9420e' 
  AND token = 's/2p9doqCqQ6PCKwJ9k/AUombjuemti4xwitiWkyiBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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