SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '31cdb2283668b3acecd5b8706543ce6f61d08910453077a3a714c32dcc7aabcb' 
  AND token = '2iTiIGOI63k+03azL+hqfE97dPKOsJnMpzD6BCOv29s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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