SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d919525578992384955ccf7089aaaa0993f36d8ff96f27acb3677e9b38dba23' 
  AND token = 'ekhJ6yvGkmV65IV6kW8OLXeOlm2vn6IwfBePsPfLXB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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