SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f49fc98aacd54ff5f8e3b83ae8ed81200a07a0af7a41aeb28ee85ab0a8131915' 
  AND token = 'dijdd+FoZwAP05iRhFKQ9Ld1oPv9cNPhL81HFlrheuw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}