SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'df00f0023e69612f5642c5bb6497b1b2a575bbccd02b538b39d4106b70afbe7e' 
  AND token = '3YKUdI+rIcTPWDHXX93g4R44NAUi0M5/Teuu089XPe4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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