SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e339e02c7f6929725559f08acde77e4a38a8df7e4b0cd91f68aa72adeb238393' 
  AND token = 'YrVKc+vVX1vBY/TOgay+q7h92o6Clu/ZLgvm7t7DyME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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