SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7079a4510dc29226881c9aadf368b6f92c5cd67f706bc875c5adf8631ed8ff0' 
  AND token = 'hjC+JK91l6pZCVQWyiVNxqrF7y+AcukuOiRZ+N2mx18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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