SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f43d8a17501c059d44d209a0b6d44fec6908ed5b4e2fb33d85b579c667ea593' 
  AND token = 'yyM2ssdCagu2VYJI8H7cjyOWb+vvBADUwJmtXZ7I4po=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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