SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6a20eb1cf98b1d0d582f24f1b3ac176aa8ec3d3f28558170d306a341c261731c' 
  AND token = '5ymQ2tPzNuLfjWmZjxtaXtLwoh05UtNuDydNSsXcvu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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