SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5c07652b274d0c42913d7c8de735c08e35a7c294dca1ccda0c881795efcb329' 
  AND token = 'ccS5IyCTcrfjM7niomychan3M7prkXVT6u4NdyNNL1E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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