SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf0a01ab5e3d86e070195c618aa828018ab46e7b1a7d2b7587766f404aa9d756' 
  AND token = 'na8nm9G3PP7yxGNTHg5Msks0N16UJ7q0h6t0cAwWw/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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