SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '270857464f9546507d525c0b5834af935ca39f5ef26d51ef7888bffdd94944c0' 
  AND token = 'cByIftnZer+rYw0C10X3NWgk8u2ISRjXAUIRv10Gp+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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