SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7988385a032c9f64022374778d46900b2cac2813988c9cb025bf4e9434c45399' 
  AND token = '2F6whabrZ5chvuVQKqa+jkW8mmj0Wi9sBp31YdwemT4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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