SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bbdc56d935e55367438e87b97b09155d26d0dd61cba4582e6aa212727c713bf' 
  AND token = 'wiEr1MjvzY2pNo62aSMiITI49iXxc/eVJQsQPHstUwE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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