SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b86cc960611b8f1ca157332b9a69e47cf3f4626917fe91077df87ca4301c6f8' 
  AND token = 'y4pgA6FPSrr+PvJHXrFDdLVrz56L4P+n+AAvREQUH+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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