SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75f8f897b1d184ea8faf2689be205f70c15fe25a1b8da62c2318d30afe26d9fd' 
  AND token = 'FSzuUlvH3ro/7qhkCCi9Vg5Lvvyzp3wEITIKuBQrLEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.03354

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}