SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ca9b6336969a7c9762f27c1856f0ccb2826e804f37db418331d6df8b535fa54' 
  AND token = '6hO2v24Nf+G7vYpC3/JVSrTZODLnrk01PhgmqISKGhw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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