SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98b1f6395a445a1b989da44b226b487aba326d3d4189bfd095b2bb92f05bb358' 
  AND token = 'DQyjEX4t6tP0QqebJllMT2qYVjT3zYPraDRn1Xr+8ng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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