SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '63a1201f96a2b0a0781c285b2384b01d0f12b37f2a0b719adc023a59b4164588' 
  AND token = '94rHz/G1fRPPPmCiRy8hTVQ8ORVJ0AjHb3vbkVf5+qs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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