SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3718f98e435269764d2b5f5b947785a8927fabe89a37be0e3afe23f0dd4406a5' 
  AND token = 'aiugKXm1BGVFD0owHhZJQow8KUOuh8F6p4alaQbUKTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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