SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a09c8bf4e3faa80741b0a832ba02fb47c1740b57ab5eb6e10d4c07e66edcd293' 
  AND token = 'mZyiSnKXUCFlYt3iaVeqYabJqco9DvyMaAgj+cpX7rI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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