SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '858ff54f61007ad5939ea36474cb00040ab1b249081eed8aa6f43ea0d2d73c5b' 
  AND token = 'PsauAju17rgRXjV5S5XZ7BEMn8N+D7nLZh6mIOl5Row=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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