SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe1cd7bfdd991d4d36eb6928465b1b81b253ccfc2bbe9eca3d7b87ccc2f2ee3f' 
  AND token = '9bgtEnwvijmDEBNTvnlmjNun2gkpb+OwDDKrRjdrugQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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