SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4fb4c34fc899d512e714a2f2abcc935f96984f4b7e4cb26d3df28a313867c987' 
  AND token = 'MJrlefnwcoVHY++bBRcFG9ZxeKWkfZZk6cHPoSK7sjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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