SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bed118b5115e995720e8f2229ffaad7f113c2cfb13e1b932112bb8193977fec' 
  AND token = '9KbfnGv2By0tqinXAOkRTMhPSi1k+LVYzRrNTnQkhzo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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