SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b789c4960077e51fa3dca082f66f969aaf508b78f36edc4713716424113908a9' 
  AND token = 'ZzAM2jr74iXgEcvSc3Kwqiq8uT1Vj+AYdeDvOg5LXNA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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