SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6023ef09b5eadaccf72094f0784e3213c6230eb5f7ad81ee76b43809b8a1b999' 
  AND token = 'rOg7c+iePke8kxVcPcsWJdFdB5BD6Q1PAzzjGrvyp/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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