SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '297138b8932e74efdfda4eb9cd2b2af901412d626f9dad37488d83a6d5af6006' 
  AND token = 'u7WOsEr5hJOL7S4zXwujDvU78wFmWBeDpZAD6KO23pA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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