SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02e9469dd89f75d2d58dcab943bdec207d86473bed8d42055788ded8dcb192f9' 
  AND token = 'WOdKNqpkMGLm7u3PmUTjnpE0W9EBu5anU8KjQb0d8/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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