SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2d0f6ad841842536e9c28b5972c232e3ffda8ce79ea8c59cd3cd05cf628171b' 
  AND token = 'XcCBf7893wrcRAZd3YK2Z4fURO7d8XBdG5bVov7NloA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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