SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c52ed6b24892671a397cbc3c62b3a85a4597442173ea91fd759606c64181c4d1' 
  AND token = 'MtszeF3tHh7gmwFl84PcmUZ0DjtiwaFjYTwDhTzfDwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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