SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '619ef93c197fd5ebf0ade651370524143a01547f2f0fd3560af3638332206e1f' 
  AND token = 'I3jdcgEipzg0edZAFoR8B/3LP38NQ20gbtWFaZTCB1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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