SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7c2df390a6b672bc5e09d5bdd4f925f0b38d6255c3591d4c169c05ac05216eb' 
  AND token = '9xGoCOkQLD+WrW5t5Wthw65EHt0FceRG7rzuSsK3bkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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