SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4eb7dc63f277bf825f81bed17c9839a239f05c87c6e9578e462c85ba826a91db' 
  AND token = 'JLVlHW2sJgYiv025vY/xKzaztPgnGMoTG4nLFpi/XbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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