SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6669315946db81a602672f56c8066843b5fe2455ee211889b23d87cec47cd630' 
  AND token = 'gS4jSNqpnVY+zjuyZcltnAIX+xCH04WuE1wLTB2CuM4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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