SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ad10ed67041ae02a7644c0e87ca2b72ca64badda54584c16a69ff9ea4ba3ad4d' 
  AND token = 'dUrjW12rlOKfpCnf3A1uYgE3DScB/f4FwDYaRFBFyOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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