SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00cdf5246a1478fb12723013de44985ccf399bd025889f35cf2c022a2afaa000' 
  AND token = 'R4DvXTxxJux82qiwcoaLpeSBiLi6x0eDG3xFqCFZvUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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