SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97152831ddcd3428038fdc5884718d6222096e56b7e0b3ae3afd45c905ba3e02' 
  AND token = '1euvxOXDtUUUCOVv8jhiWfQNdxFqXzmjKGzWAfRTobs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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