SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a58d2537dff76a4c5f2f3bd3ca03dbf991262719a62f15ad26ac696e8fbfcc35' 
  AND token = 'z9jg43vFY4+nzWV0oIOceGOSL8AuenhgmtUzUJfMCcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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