SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fc7f076cb18800a44d72f661fe5c5f13b942a4c07c18459bbb7dbcded7af9b86' 
  AND token = 'bI8bl2UJcpF+MPR4mlHEMzO2lwMADiaem3B6O596YqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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