SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92698c432de3056af67bcf32c15f47a8a2c9212e0a0d41138c25df9dbcb97388' 
  AND token = 'g+rYRy1KmcYmgmB45VE5zZjSuDxQL15yVFgng4/o2Vk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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