SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ce5800fc016ba7ba188f1c30c11adcf5030c394271cece8774b631be882bb73' 
  AND token = 'OPYheN+j1+uTO91KPUKuleexwgfFi1vaRDbrP71jIbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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