SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15c482b12c62cfcd96bb2735d603ee26d5e04730b14dbb4c5be861689e327d87' 
  AND token = 'lGOmsCto/mlUwyDIx3s1FIKa5t9dsmae/bYVHKChtz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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