SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb0286ff6dc548237949b4554a57516c74277af7826563018d3d55c1acee31e5' 
  AND token = 'tSeYgIWnyWESRcNWgAchG0BNacyn2DsmjTdpsXSEU8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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